Forgotten engineering techniques

[Martin KyteParticipant @martinkyte99762]

ooooh good that means I can ignore the people who moan about the forum then.

I could suggest that if you only want data then buy a text book.?

regards Martin

[Roger Williams 2Participant @rogerwilliams2]

Hello all, I cant for the life of me understand what the problem is !. I presume someone dislikes Larry Coleman 1's posts, thats what appears to me anyway. Ive found them very interesting, along with all the other answers. Perhaps Bogstandard would enlighten me !.

[Hamish McNabParticipant @hamishmcnab62554]

I was delighted when this post started as a newcomer I thought I would learn and its now a.history lesson that is of little interest. Please keep on topic.

[magpieParticipant @magpie]

Perhaps the thread title should have included the word "model" in front of engineering. I have to say that I fail to see the need for model makers to know how to straighten 10 ton prop shafts.

Cheers Dek.

[jason udallParticipant @jasonudall57142]

Maybe off topic.
Forgotten engineering. .etiquette. ..

I sometimes read these and wonder if I am particularly thick or thick skinned..I don’t see the offence that some find.

Most of the stellar engineers ( stars not engineers of stars) I have met or conversed with have a certain humility and willingness to share experience.
Some pride yes but seldom boastful or proud.

[Neil WyattModerator @neilwyatt]

I am increasing frustrated watching this thread descend into the mire.

I expect threads on this forum to wander off track, but the nature of some recent postings in this thread is now inappropriate.

Unless this discussion can continue in a more civilised manner I will be closing this thread to further comment.

Neil

Administrator

[Peter BondParticipant @peterbond14804]

One thing I'd point out is that while I've no immediate need to straighten a propshaft, I'm nonetheless interested in hearing how it was done for 2 reasons:

1. It's not something taught generally in engineering degrees. Forging as a prototyping method would be another example.

2. It is the sort of thing that can find odd applications elsewhere. As a mech eng turned software eng turned jeweller, there's all sorts of bits from other disciplines can be hijacked and pressed into service.

On soldering – I don't think I've seen this one so far – using a bit of yellow ochre mixed to a paste, or rouge (jewellers' rather than makeup), clay or Tippex (caveats on VOCs) works to stop solder flowing where you don't want it. I use Tippex on torque plates when making mokume gane to prevent the metal fusing to the torque plates (although I've seen good feedback on the use of boron nitride welding prep sprays too, so I'll have to give that a go soon).

[FMESParticipant @fmes]

wow, is it really that bad?

I log on to this forum many times during the day just to keep up with the different discussions, and enjoy some of the random topics and the memories they sometimes bring.

I am rather amazed that it could be thought that the myriad of hints and tips that must exist within the engineering world could be covered in just a couple of pages, when I first saw the title I likened it to the 'What did you do today' thread, which could develop over many articles.

Sometimes even the most simple tip or comment could inadvertently solve a long term problem for someone, so in some respects whatever is written by someone may possibly be found to be of interest to someone else, and I believe it may be wrong to censor an article just because it may be found not to a persons taste.

Oh, and an apology Neil, for posting 'another' off topic item.

Sorry.

[Bob Brown 1Participant @bobbrown1]

"mokume gane" had to google that jewellery is not my thing, but interesting as it could be useful when soldering up boilers to stop solder flowing all over the plates.

Bob

[Ron ValeParticipant @ronvale24328]

About 11 pages ago someone mentioned 'toolmakers buttons'

Can i respectfully ask that this thread be put back on track to explain how these work etc etc etc

And after trawling though a lot of who gives a ? posts where can i get the last two hours of my life back please

[“Bill Hancox”Participant @billhancox]

Posted by Ron Vale on 22/01/2015 23:06:33:

About 11 pages ago someone mentioned 'toolmakers buttons'

Can i respectfully ask that this thread be put back on track to explain how these work etc etc etc

And after trawling though a lot of who gives a ? posts where can i get the last two hours of my life back please

Ron

Here's a start **LINK**

Bill

[John OlsenParticipant @johnolsen79199]

OK, let us suppose that you have a need to make some holes in a flat face, and they must all be accurate to size and precisely located with respect to each other and the edges of the piece. If you mark them out and centre punch then drill in the usual way the drill will wander and the marking out and punching will also allow errors. So instead of drilling out to full size, you drill and tap a small hole where each hole is to be. (With reasonable but not critical accuracy.) Then you take your toolmakers buttons and screw them onto the job at each location. The holes in the buttons have a bit of clearance, so now you can adjust the buttons so that they are in the correct location relative to each other and the edges. You know the size of the buttons, so you can set the spacings using accurate pieces of packing or by careful measurement, depending on the level of accuracy you want.

When the buttons are all in the right place, you can set the piece up in the four jaw chuck, and use the dial gauge to set one of the buttons to be centered. Then you take off that button, and drill and bore the hole to the correct size. Just drilling won't do, as the existing tapped hole may be off a little, so you want to bore it so it is trued up correctly on the axis of the lathe. You then set another button up to be concentric, and bore that one. When you are finished, all the holes should be accurately placed.

The same thing could be done on a mill, setting each button on axis in turn, but it is usually easier to do coordinate drilling on a mill, eg use the graduated handwheels to set up the coordinates of each hole in turn. (Or the DRO if you have one.)

Buttons are easily made from small slices of round stock, faced on each side. Quite commonly each face is recessed a little. For occasional work they need not be hardened. Stock that is accurately ground to size is nice as it can make the arithmetic easier. (I want two holes 1.25 inches apart and my buttons are made from 12mm ground stock….what size packing should I use between them?)

For some awkward jobs it might be better to use the button approach to make a jig, then use the jig to make the holes in the job match. Making the holes in the bedplate and cylinder block of an engine like the Stuart twin and compound launch engines would be an example of this sort of thing.

John

[Larry Coleman 1Participant @larrycoleman1]

Good description John

How those toolmakers buttons came about is a lot of small tool rooms did not have access to a machine called a jig borer and when you make what is called a follow on die or a die which has say five stages before a component is completed the accuracy between stages are very important. Because the strip progressed by what is called a crop stop or a pilot punch if the second hole is .001" out it is then multiplied x 4 at the final punch process.

So you have to be able to at least get those holes within .0001" and you can not mark out Centre punch and drill to that accuracy. The die block is then ground square and you choose an X & Y position. After marking it out with a height gauge you centre pop each hole position and drill & tap for the button screws.

Each button has about .060" of movement and is a miniature cylinder square so you measure from the X side minus half the button diameter and then from the Y side minus half the button diameter.

Then you place the die plate in the chuck and dial the front face rotating true. Then you dial up the button until it runs true then you check the plate face to check its still true. You repeat that process for each hole always measuring from the X & Y.

On most occasions you measured with a depth micrometer so your hole can be within .0001"

Now I earlier brought up the cylinder square because the toolmakers buttons are miniature cylinder squares.

Help me out here John is that to complicated ?

I will come up with some pictures shortly.

Larry

 

Edited By Larry Coleman 1 on 23/01/2015 04:06:32

[Larry Coleman 1Participant @larrycoleman1]

End view Toolmakers button

Edited By Larry Coleman 1 on 23/01/2015 04:47:49

[Larry Coleman 1Participant @larrycoleman1]

Now getting back to what I was saying before. With small hole taps try and get Gun taps. They only have two flutes and when used for hand tapping you can not beat them. Must use tapping compound for best result.

They are a little bit more expensive but its worth it.

These taps are intended for use in tapping heads used in a drill press.

Larry

[Larry Coleman 1Participant @larrycoleman1]

The attached picture is a tapping head for a drill press. All the taps used in them were gun taps.

[Neil WyattModerator @neilwyatt]

Thanks to recent posters for getting this back on track.

Neil

[Larry Coleman 1Participant @larrycoleman1]

Hey Bob

I must apologize. I made a mistake you were not the person I was aiming for.

Sorry Bob.Please accept my apologies. That comment was aimed at the person winging not you.

Larry

Edited By Larry Coleman 1 on 23/01/2015 11:26:57

Edited By Larry Coleman 1 on 23/01/2015 11:39:07

[Bob Brown 1Participant @bobbrown1]

we all make mistakes said the hedgehog climbing off the lavatory brush

Bob

[Harry WilkesParticipant @harrywilkes58467]

Posted by Bob Brown 1 on 23/01/2015 11:30:15:

we all make mistakes said the hedgehog climbing off the lavatory brush

Bob

H

[colin hawesParticipant @colinhawes85982]

Getting back to the toolmakers button advice I would like to offer a tip: A slot drill is the easiest way of truing the off centre hole on your job before finish boring. Colin

[MuzzerParticipant @muzzer]

Gun taps are known as spiral point taps in the UK. They are intended for thin or open holes and the swarf is ejected forwards, unlike a spiral tap which is better for blind holes and generates swarf that comes back towards the chuck.

[colin hawesParticipant @colinhawes85982]

If you have been unlucky enough to get a wobbly centre–drilled hole it can be recovered by trueing with a slot drill and recentred with a larger centre drill Colin

[colin hawesParticipant @colinhawes85982]

A taller pair of vice jaws with a slit through them is a safer way of holding very short jobs when milling the end as the job is then held in the middle of the vice. Colin

[colin hawesParticipant @colinhawes85982]

Make a soft centre to hold in your 3 jaw lathe chuck, It needs to be skimmed each time it is used but it saves the tedium of removing the chuck each time and is as true as it is possible to get. A cranked lathe carrier is used with this method driven by the chuck jaw. If you have lots of troubler getting the centre to run true then this is the way to go! The soft centre needs to have a step diameter on it to avoid getting pushed back into the chuck under heavy cutting. Colin

[Author]

Posts